SkMojo: test linking Skia against the Mojo SDK

dm/DMSrcSink.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
@@ skipping 337 matching lines @@
     explicit ViaSingletonPictures(Sink* sink) : Via(sink) {}
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
 class ViaTwice : public Via {
 public:
     explicit ViaTwice(Sink* sink) : Via(sink) {}
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
 };
 
+class ViaMojo : public Via {
+public:
+    explicit ViaMojo(Sink* sink) : Via(sink) {}
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const override;
+};
+
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED